I purchased last year a Chinese Tube Preamp (Ming-Da). It is excellent as far as build quality and sound go. Obviously, it came with all Chinese tubes: 1x6n6, 2x6n3, 1x12AX7, and 1x5687. This sounded very good, but it didn't really have the spark that I remembered from the tube amps I used to pillage in the seventies from the garbage, fix up and connect to speakers. So I started tube rolling.
By checking this forum and other sources, I discovered that the single biggest difference would be swapping the 6n3 tubes with Western Electric 396A used old stock. This made a huge improvement in sound--wider-appearing soundstage and very nice tight bass, though still less bass than I like.
Then I added a Telefunken used old stock 12AX7. It sounded a little more "technical" (only way I could describe it), but I liked it more than the chinese one.
I swapped out the original chinese 5687 with a Tung Sol. This didn't seem to make much of a difference, but I kept it in.
Now this is where things start to get really interesting, and particular to this thread on Soviet vs. Chinese tubes: Two months after receiving my amp and it working fine and as above being tube-rolled, it started blowing a fuse immediately after being turned on. I tried putting in all the original tubes, etc. but nothing worked. As it turned out, the only tube I had not changed was the original Chinese 6n6. I brought that to a local tube shop off Canal in Chinatown (I'm in Manhattan, Lower East Side) and they told me it was not testing correctly (whatever that means). I asked how long to order one from China and the answer was about a month.
That's when I went online (eBay). I found a guy selling 6H6p Soviet tubes, mixed, from the 70's & 80's, new/used old stock. 10 for $20 plus $10 shipping. I figured the worst that can happen is I lose $30 bucks. At the same time, one of my colleagues who is from Russia, said is daughter-in-law was going to be travelling there, so he'd ask her to look for me as well.
Finally, the Soviet tubes arrive (from the eBay seller) after only 1.5 weeks, I hesitantly popped one into place, and I have to say that I was simply stunned by the difference from before. I listened to Coltrane, which was the last thing played on my preamp before the tube problem. Music just seemed to open up like a fine wine after it breathed for an hour. The output seemed louder by just a slight amount (I had to turn down the amp by a tad for the same sound level as before). This one Soviet tube alone made as much difference as the UOS 396As had done previously. I was very happy.
Now, 2 months later, my colleague's son gave him the other 6H6p that he had asked about for me, and I had also mentioned that if he saw them, I wouldn't mind having a set of 6H3p also (in case my 396A die and I can't replace them for less than $50!).
Just to try them out, I popped the Soviet 6H3p in place of the Western Electric, and it was an even bigger positive difference: now I got a definite kick and tap on the drum kits that wasn't there before (unless I made it very loud), and the bass was punchier and heavier than before, with no muddiness. And on top of that, the cymbals and hi-hats were more distinct, as was the sound of fingers on bass/guitar strings. And best of all, when I put Coltrane back on, the sax never sounded better.
In short, I really really like my Soviet tubes, and I might try to replace all of them with old stock soviet--though I don't know what would be available for the 5687 (I couldn't find a direct Soviet replacement, yet). I do have a new Sovtek 12ax7lps, but it's not much different than the telefunken, surprisingly, and just a little less warm.
Well, that's my story, FWIW!
Dave
By checking this forum and other sources, I discovered that the single biggest difference would be swapping the 6n3 tubes with Western Electric 396A used old stock. This made a huge improvement in sound--wider-appearing soundstage and very nice tight bass, though still less bass than I like.
Then I added a Telefunken used old stock 12AX7. It sounded a little more "technical" (only way I could describe it), but I liked it more than the chinese one.
I swapped out the original chinese 5687 with a Tung Sol. This didn't seem to make much of a difference, but I kept it in.
Now this is where things start to get really interesting, and particular to this thread on Soviet vs. Chinese tubes: Two months after receiving my amp and it working fine and as above being tube-rolled, it started blowing a fuse immediately after being turned on. I tried putting in all the original tubes, etc. but nothing worked. As it turned out, the only tube I had not changed was the original Chinese 6n6. I brought that to a local tube shop off Canal in Chinatown (I'm in Manhattan, Lower East Side) and they told me it was not testing correctly (whatever that means). I asked how long to order one from China and the answer was about a month.
That's when I went online (eBay). I found a guy selling 6H6p Soviet tubes, mixed, from the 70's & 80's, new/used old stock. 10 for $20 plus $10 shipping. I figured the worst that can happen is I lose $30 bucks. At the same time, one of my colleagues who is from Russia, said is daughter-in-law was going to be travelling there, so he'd ask her to look for me as well.
Finally, the Soviet tubes arrive (from the eBay seller) after only 1.5 weeks, I hesitantly popped one into place, and I have to say that I was simply stunned by the difference from before. I listened to Coltrane, which was the last thing played on my preamp before the tube problem. Music just seemed to open up like a fine wine after it breathed for an hour. The output seemed louder by just a slight amount (I had to turn down the amp by a tad for the same sound level as before). This one Soviet tube alone made as much difference as the UOS 396As had done previously. I was very happy.
Now, 2 months later, my colleague's son gave him the other 6H6p that he had asked about for me, and I had also mentioned that if he saw them, I wouldn't mind having a set of 6H3p also (in case my 396A die and I can't replace them for less than $50!).
Just to try them out, I popped the Soviet 6H3p in place of the Western Electric, and it was an even bigger positive difference: now I got a definite kick and tap on the drum kits that wasn't there before (unless I made it very loud), and the bass was punchier and heavier than before, with no muddiness. And on top of that, the cymbals and hi-hats were more distinct, as was the sound of fingers on bass/guitar strings. And best of all, when I put Coltrane back on, the sax never sounded better.
In short, I really really like my Soviet tubes, and I might try to replace all of them with old stock soviet--though I don't know what would be available for the 5687 (I couldn't find a direct Soviet replacement, yet). I do have a new Sovtek 12ax7lps, but it's not much different than the telefunken, surprisingly, and just a little less warm.
Well, that's my story, FWIW!
Dave
